As soon as you check in to a hotel that does things legally, you will instantly have a new TM30 on file in whatever province that is.
You can then ask for a print out of the TM30 from reception, and bring it to the local immigration office for your 90 day report.
If you have a TM30 on file that is different from your home province you won’t be able to do your 90 day report online using your home address, but i am not sure about that.
i have heard of police showing up to arrest foreigners on overstay at their guesthouses, which they can see if you file a new TM30 on an expired visa. Someone might want to confirm that.
and they will not care if you are a pensiuner or mother teresa, if they catch you it will be off to immigration lockup and deportation at your own expense.